Are both connections (command line and graphical terminal) using the exact same connection parameters (user, server)?
When connecting from the SSH Tectia Terminal are you using a profile or the "Quick Connect" button?

Can you paste the log messages that are produced when the connection fails?
These can be found from the "Logs" button in the SSH Tectia status window.

UPDATE:

So if I understand this correctly, the connection works from host A (solaris) to host B but not from host C (windows?) to host B.

Are you able to connect form host C to host B using the command line? If not please try again with verbose enabled paste the error that you see:

Hmm, I see the error diagnostics was not really perfect in 6.0 version stil. That should be much better now in 6.2. But it seems that the broker component is for some reason not starting. You could get high detailed debug info by trying to start non-GUI version of connection broker this way (in version 6.0):

"ssh-broker-cli -D3 --console"

If it does not seem to help try higher debug levels (-D6 should be enough). If you find some error message that could explain the problem, post it here please.

From the logs it seems that the TCP connection has been disconnected by the server (or something in between). A bug in broker then causes it to report meaningless error code (actually the code reported by server is not recognized by broker). In fact it looks like the server is responding with reason code SSH_DISCONNECT_RESERVED or some other reason code not defined in RFC4253.

Are you sure that the server B you are trying to reach is reachable from your Windows host C and that SSH server is running there? What SSH server is on that server? And is it configured so that it would accept connection from your Windows computer C?

Yes, I can ping the server.
We can ssh to that server from Server A.
Version: 11.10.0,REV=2005.01.21.15.53
It is configured to accept and has worked in the past.
Is there some type of Tectia DB that can be purged, etc?
Also, what version of SSH does Tectia currently use?

And restart the connection broker with default configuration, to avoid any configuration problems. For the server side, you would have to investigate what is actually happening there upon such failing connection request.

The fact that computer A can connect to computer B has little or no relevance to computer C connecting to computer B. There are many things that can be configured to prevent such connection. One of them is SSH server configuration of course. It many be configured to refuse connections from some servers or to accept connections only from certain servers. It may fail to resolve the client computer's hostname and refuse such connection. So next step would be to see what is going on on the server side.